Method of treating metal pipe.



UNITED STATES PATENT OFFICE. GEORGE A. BENNE Yi B F PIT'ISBURG, PENNSYLVANIA. 7

METHOD OF TREATING METAL PIPE- Specification of Letters Patent.

Patented Oct. 2, 1906.

To (1,7 6 whom, it may concern.

Be it known that I, GEORGE A. BENNEY,a H

' citizen of the United States, residing at Pittsburg, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Methods of Treating Metal Pipe, of which the following is a specification.

My invention refers to an improvement in the'method or process of treating pipes for the purpose of adapting them for any use where the pipes are exposed to moisture, acids, or gas. I

The invention consists in first cleansing the surface of the pipe, then subjecting it to a pickling operation, then flushing the pipe, then baking the pipe, and then coating it.

Heretofore pipes have been treated by first pickling them to loosen the scale or other adhering matter, which was then removed by any suitable means, as a sand-blast, and then coating the surface with a suitable material, as enamel or paint. I have found that the handling of the pipe after being subjected to the sand-blast, subsequent to the pickling operation, causes oxidation or otherwise so effects the surface as to prevent and largely interfere with the successful application and adherence of the final coating or enameling, and my present improved method is designed to overcome such difliculty and to roduce an efficient evenly-coated pipe hot in the interior and exterior without loss of time,

in the manner hereinafter described.

In carrying out my improved process I first subject the interior of the ipe to a cleansing or scouring operation, as 8y the use of a sand-blast, for the purpose of removing any adhering particles and of cutting away any projections, fins, &c. The pipe is then immersed in the pickling-vat containing a suitable pickling solution of diluted acid, &c., which thorough cleanses the pipe from any adhering particl es or foreign matter, and when removed from the tank the pipe'is covered with an adhering thin coating or film of the pickling fluid. The pipe is then flushed with hot water in any suitable tank under pressure, either steam orv hydraulic, and alowed to remain therein until the pipe is thoroughly washed, when it is removed and placed in a baking-oven in which it is thor oughly dried and heated to the desired temperature evenly throughout the entire body portion. The pipe is then removed from the oven and immersed in the coating-bath, by which process the coating or enamel is a plied while the pipe is still hot from the ba ing-oven. The pipe is then replaced in the oven until the coatin is thoroughly set, when it is ready for use.- he advantage of so applying the final coating or enamel is that due to the heated condition of the pipe the enamel or coating will thoroughly fill all pores or interstices and will at the same time be deposited evenly over the whole surface, due to the partial melting effect of the heated pipe. These operations are carried on successively being handled by suitable mechanism, and when finally removed from the coating-bath and allowed to cool the covering enamel or aint thoroughly coats the entire surface, goth inside and out, and when baked will be found to be of an even thickness throughout. The advantage of first cleansing the interior of the pipe by the sand-blast or other operation and then pickling it is that the cleaned surface of the. ipe is not subjected to the handling after the pickling o eration, as it is when these steps are reverse (andup to the time when the pipe is immersed into the flushand without loss of intervening time, the pipe ing-tank of hot water it is protected against these steps are carried out as escribed that the results are hi hly successful.

Having descried my invention, whatI claim is 1. The method of treating the surface of metal pipes consistingin first cleansin the surface of the ipe by a sand-blast, ic ling the pipe in a di ute acid solution, flus in the pipe with hot water under pressure, ba "mg the pipe to raise its temperature, and then applyin a coating to the treated surface, substantial y as described.

2. The method of treating the surface of metal pipes consisting in first cleansing the roo In testimeny whereof I my signature in presence of two witnesses.

the pipe in a di ute acid solution, flue the GEORGE A. BENNEY.

pipe with hot water undel pressure, mg the pipe to raise its temperature, then a 1ya. coating to the treated surface, an t en Failing the} coated pipe, substantially asset ort surface'of the. ipe by, a. sand -blsst; bait Witnesses: CHAS. S. LEPLEY, C.M.IOLABKE. 

